Reduction of refractory ores.



F. J. TONE;

EEDUGTEOII 0F REFRACTORY GEES.

APPLIGATION FILED AFB. 2,

Lfi lfil I Patented June 4,1912,

WITNESSES iNVENTOifractory 35 tion of mace and releasing FRANK-'3'. TONE, or NIAG nArALLs, nEwYonK.

BEDUGTION' or REFRACTORY onus.

Application filed April, 8, 1907. Serial No. 366,915.

To dZZ'wfiom it may concern: Be it known that I, FR N -J; Tons, of

Niagara Falls, Niagara county-New York,

have invented a-new and usefullmprove- 5 ment in. the Reduction of Refractory Ores,

of which the following is a full, clear, and

exact description, reference being had to' the v I, accompanying drawing,

forming part of this Specification, in which the figure -is a 0 sectional side elevation showing oneform 'of electric furnace for-carryin out my invention.

The invention relates to reducing of re-' compounds in the electric furnace, and particularly those compounds which are more or less volatile at the temperature of reduction.

The 'objectof the invention is to reduce the lossand thereby increase the efficiency in the electric furnace reduction.

While the process is generally applicable to refractory oresor larly those which are volatile at their reduc tion temperatures; I will describe my invention particularly with reference to the reduction of silica compounds for the manu-I,

factu're of silicon, silicon alloys and sillifcides.'

of carbon and silica in the proper proportions, the product of the reaction in the elec tric furnace being silicon andzca-rbon monoxid gas. During this process the evoluhe carbon and 'monoxi'd gas is rapid, and tendsto carry out of the furnace a certain proportion. of va- .por of silicon and silicon compounds, thus reducing theoutput. and loweringthe'efliciency. This loss" by volatilization is the most serious of-alLlosses taking place during the process. I have discovered that thicse losses by volatilizat-ion can be greatly reduced by confining the gases in the furthem'only at or above a certain normal pressure. The furnace may be constructed n many different ways'for accomplishing this desired result. I prefer, however, to 'inclose the furnace by suitable means to make it impervious and to provide outlets having means for releasing the gases when the pressure reaches or exceeds a certain predetermined amount.

. In the drawing, Tshow anjordinary type of arc furnace, having a crucible 1 making 7 is a weighted valve normally exltthrough the top or cover. One or more compounds, particu- Heretofore 1n the production of silicon, 39 it has been customary to employ a mixture.

up the side walls and bottom, and p'rovided gvith a tight cover 2. ,This cover fits cl'osely walls. 4 represents the other electrode, which is preferably mounted upon acarbon base block -5, constituting the other terminal of the furnace. i

.6 is acharging hopper,

having 2 raising and lowering bell, or other suitable means for feeding the chargeinto the furnace, and closing a gas of these controlled gas outlets may be pro vided, by .which the exit of the gases and volatile products may be cont-rolled and around the electrode .3 and upon the side Specification of Letters Patent. Patent ed u'ne 4,1912- their pressure thus regulated' The charge of the furnace is shown at 8, 9 being the usual tap hole at the bottom.

In the operation of. the furnace, the zone of reaction formed bythe arc, or otherwise,

maybe surrounded by a considerable body of charged material in a finely ground nonporous state, or of'such character that the exit of the gases is impeded; and in this way it is possible to raise the pressure of the gases in-the reaction zone to a considerable amount above their normal pressure. Silica has an appreciable vapor 1181151011 even below thepoint at which it fusesand below'the point .of reduction; and by increasing the pressure in the-reduction zone,

the maporizing point oft-he silica and reduced silicon is raised, resulting in prevent 7 ing to a large extent the-volatilizing of the products,

The condensation of thevolatile products is also assisted. I The process may be applied to reducing other elements, subject to volatilization losses, such as aluminum, manganese boron, &c.

Many changes may be made in the form and arrangement of the. furnace, &c.., without departing from my invention. I claim I 1. The-method of reducing metallic compounds subject to volatilization losses, consisting in electrically'heating a mixture of the compound and a redu g g t Within the reduction zone to a temperature sufiicient to cause volatilination of the compound and its reductioh by the deducing agent, and maintaining the gasesinthe reduction zone ..under a. raised pressure suflicient to reduce volatilizationlosses and-to promotecondensation of the reduced product but insufiicientto wholly of an electric arc furnace prevent volatilization of the compounds of.

gases in the reduction zone undera raised of reducing silicon com-' pressure sufficient to reduce volatilization losses and to promote condensation of the, reduced product but insuflicient to wholly prevent volatilizationof the compounds of 15 the charge. 4

In testimony whereof, I have hereunto set my hand. I

FRANK J. TONE. Witnesses:

F. I. Pmnon,

CHARLES CHORMANN. 

